External metal lap.



L. S. RASMUSEN & H. B. CARLSON. EXTERNAL METAL LAP.

APPUCATLON FILED FEB. 2a, 1916.

Patented Apr. 3, 1917.

2 SHEETS-SHEET I.

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L. S. RASMUSEN & H. B. CARLSONJ EXTERNAL METAL LAP.

APPLICATION FILED FEB. 28, me.

Patented Apr. 3,1917.

2 SHEETS-SHEET 2.

IIVI/ENTORS 00d Lorerme @S'. Pasmusfn [fer/27cm B. Car/mo;

ATTORNEYS LORENCE S. BASMUSEN, OF ROCK ISLAND, ILLINOIS, AND HERMAN B. CARLSON, 0F DAVENPORT, IOWA.

EXTERNAL METAL LAP.

Specification of Letters Patent.

Patented Apr. 3, 191?.

Application filed February 28, 1916. Serial. No. 81,006.

To all whom it may concern:

Be it known that we, Lonnncn S. Ras- MUSEN and HERMAN B. CARLSON, a citizen of the United States and a subject of the King of Sweden, respectively, residing at Rock Island, in the county of Rock Island and State of Illinois, and Davenport, in the county of Scott and State of Iowa, respectively, have invented certain new and useful Improvements in External Metal Laps; and we do hereby declare the following to bea full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to grinding and polishing, and more especially to the external treatment of curved surfaces; and the object of the same is to produce an improved lap or tool for holding the abrading material and applying it to the exterior of a rapidly.

rotating cylindrical piece of work. A further object is to so construct the lap that it will adapt itself to work of various sizes, within limits, and to inequalities on the surface of the work being treated.

These objects are carried out by the construction hereinafter more fully described and claimed, and shown in the drawings wherein Figure 1 is a plan View of the simplest form of this improved lap, Fig. 2 is a side elevation thereof partly in section, and Fig.

3 a vertical section on the line B-B of Figs. v

larged sectional detail of a slightly modified form of handle.

Fig. 6 is a side elevation, partly insection, of another form of this improved lap, showing also a lining therefor, Fig. 7 is a vertical section on the line C-C of Fig. 6, and Figs. 8 and 9 are plan and end views of one member of the lining.

In common practice the work to be treated is rapidly rotated in a lathe or drill press, and the hole or opening in the lap is slipped over the work, while the lap is held by hand and then moved forward and backward so that all parts of the exterior of the cylindrical piece of work being treated get the benefit of the treatment. Uften the work is slightly irregular or rough on its exterior, and it becomes desirable to have the lap yield slightly to accommodate these irregularities. Also the work is sometimes initially produced in rather rough form and may vary a little from the standard size intendedbeing either a little too large or a little too smalland it is the purpose of our invention to cause this lap to adapt itself to these variations. Ive might say that in Figs. 1, 2 and 3 a simpler form of this lap is illustrated wherein .the devices for permitting its variations are entirely at one end of the tool and the handle is at the other end; whereas in Fig. 1 the said devices are at both ends of the tool and the handle pro- Fig. 2 these members are integrally united with each other at one end in a shank3. In either case the contiguous faces of the members are arched as at 5 and 6 so as to produce a normally cylindrical work opening 7.

'From this opening as seen in Fig. 2, a space or slot 8 extends toward the shank 3 and is enlarged as at 9 so as to reduce the material within the shank and to give a certain flexibility to the two parts or members, permitting them to approach toward or recede from each other as described below. At the other or outer side of the opening 7 these members have straight upper and lower jaws 11 and 12 with a space 18 between them, said space corresponding with and alining with the lowermost) isa screw 13 whose inner end or tip 1 1 bears against the face of the other jaw ll. Passing loosely through an opening or socket 15 in the other jaw is a screw 16 which is threaded into the lower jaw alongside the screw 13 as shown, and a spring 17 underlies the head of this screw and rests in the bottom of the socket 15. The expansive tendency of this spring is downward as illustrated, and therefore its normal edort is to close the space 18; whereas the tip 14: of the other screw 13 extending across this space holds the upper jaw raised from the lower aw and therefore resists such tendency. Yet if a piece of work larger than the opening "I should be thrust through it, or if irre ularities in the work should tend to sprea the jaws apart, this spring could yield and the upper. jaw 11 could rise from the lower jaw 12 as the resiliency of themetal at the shank 3 will permit. Adjustment of the screw 16 puts greater or less tension on spring 17, and adjustment of the screw 13 limits the closing movement of the jaws and the reduction in the size of the opening while always permitting their openlng movement as above 'described.

The construction illustrated in Fig. 4' is substantially the same excepting-that the upper and lower jaws are not united by a shank 3, but the screws are duplicated at both sides of the opening 7. a

The simplest form of the handle is shown at 20 in 'Figs. 1 and 2. Here it is a bar projecting rigidly from the shank end 3 of the tool. In Fig. 4 the handle 21 projects rigidly from the lower member only. In Fig. 5 the handle 22 is reduced at its inner end and turned downward as at 23 into a tongue which passes loosely through an opening 24 in the upper jaw and is removably mounted. in'any suitable way in an opening 25 in the lower jaw. As herein illustrated, the-means for mounting it therein consists of a screw 25, although we do not wish to be limited in this respect. We might say that this mounting of the handle causes the downturned portion or tongue 23 thereof to serve in the nature of aguide which permits the rise and fall of the upper jaw as the necessities of the case require.

In use, as is well known, the work to be lapped is inserted in some member such as a lathe and rotated rapidly. This tool is then grasped by its handle and brought into position, and abrading material is poured through the openings or holes 26 in Fig. 3,

or might be applied directly to the surface polish is given to the product.

of, the work. The work opening 7 is then slipped over the outer end of the rotating piece of work, and the lap moved along thereon by the operator, and the result is that the surface of the work is rapidly reduced to a true cylindrical shape. All irregularities therein are ground off, and a high hile the work opening for a piece of work of standard size will be adjusted to substantially that size, it is quite possible that irregularities on the work may cause-it to crowd open or separate the members or jaws 1 and 2 as the tool is applied; and this is permitted by the spring under the head of the screw 16. Where the jaws are connected'by a shank 3, they spread apart as would'the arms of a fork. and only a single screw 16 and its spring'l? is required. Where the jaws are connected by two sets of screws as shown in Fig. 4, they will-move apart on parallel lines y if the tension of the two springs is the same.

.orinjured, or turnout of the hands of the operator so that not infrequently an injury is caused to him or to the work being treated. By making provision for the slight yielding of the jaws or members, we avoid this contingency. While the adjustments permit the setting of the jaws or members to enlarge the opening 7 and adapt it to stock of slightly greater size, we prefer to have separate too-ls for all the separate standard sizes of work so that the adjustment need be but trivial. Otherwise the proportions of parts are not essential to the present invention, and we do not wish to be limited to details.

The construction illustrated in Fig. 6 is substantially the same, excepting that the upper and lower jaws are united or rather connected at one end by a pivot 80 and the handle 21 is here integral with and projects from the remote end of the. jaw 2. The same screws 13 and 16 are employed, and we have made use of Fig. 6 to show that the former might pass downward through the upper jaw instead of upward through the lower jaw, and that the sprin 17 need not necessarily be seated in a soc et.

Sheet 2 shows also the use of a lining made in two parts as indicated at 27, each part being nearly half of a complete circle and preferably provided on its outer side with ribs 28 which engage grooves 29 extending transversely across the jaws. These ribs and grooves may take any appropriate shape, and we have shown them dove-tailed in dotted lines in Fig. 2, because obviously they could be used in that construction or in any similar construction of the device. Each half of the lining will have a hole or opening 26 at a proper point to aline with the hole "26 through the jaw, and through these holes the abrading material is poured in as above described. This lining is of metal, and preferably of harder metal than that of which the remainder of the device is made, and its purpose is to resist wear. Yet one or both lining members may be removed and replaced when they become worn to such an extent that the opening within them is no longer serviceable for grinding a round object. The typeof our invention shown in Fig. 6, whether the lining be employed theretear rte ficiently to permit the tool to be passed over the crank, after which the jaws are connected in the manner above described. With this form or with any form of our inven tion the removable lining is also useful where the member to be ground is considerably smaller than the opening, because obviously the lining members can be slipped out of position and replaced by others which are thicker: therefore the use of removable lining members adapts the tool to work of various sizes within limits, even beyond its adaptability by the screw connection between parts above described.

What we claim is:

1.- A lap comprising a plurality of mem bers integrally united with each other at one point and bearing parts of a normally cylindrical surface at another point, a spring remote from said point of union tending to distort the position of said members and press the parts of said surface toward the work, and a screw for adjusting the tension of said spring.

2. A lap comprising a plurality of members integrally united at one point and separated by normally open. slots elsewhere, the

members bearing parts of a normally cylin drical working surface, an expansive spring tending to distort the position of said members and alter the width of said slots, and means for adjusting the tension of said spring.

3. A lap comprising a plurality of memhers whose contiguous faces are provided with complementary arches, means holding said members relatively fixed in such positions that their arches produce a normally round work opening, and yielding means tending to press said members toward each other but permitting their separation, for the purpose set forth.

4. A lap comprising a plurality of membelts. whose contiguous faces are slightly separated and provided with complementary arches, means holding said members relatively fixed in such positions that their arches produce a normally round work opening, yielding means tending to press said members toward each other but permitting their separation, and positive adjustable means for limiting the movements of said members in one direction.

5. A lap comprising a plurality of members whose contiguous faces are provided with complementary arches producing a normally round work opening, a spring tending to press said members toward each other and contract the size of said opening, and means for adjusting the tension of said sprin for the purpose set forth. I

6. lap comprising a plurality of membersfwhose contiguous faces are provided with complementary arches producing a normally round work opening, a spring tending to press said members toward each other, means for adjusting the tension of the spring, and adjustable means for positively limiting the action of the spring.

7. A. lapcomprising a plurality oi members whose contiguous faces are normally slightly separated and provided with complementary arches producing a round .worlr opening, one member having a threaded opening, a screw whose head stands beyond one member and whose shank extends across said opening and engages the threaded open.- ing in the other member, and an expansive spring coiled on the screw beneath its head, for the purpose set forth.

8. A lap comprising a plurality of members whose contiguous faces are normally slightly separated and provided with co1nplementary arches producing a round work opening, connections between the members at one side of the opening, yielding means at vthe other side of the opening tending to press said members toward each other, and a screw threaded through one member and with its tip contacting with the other member, for the purpose set forth.

9. lap comprising two members whose contiguous faces are normally spaced and are provided with complementary arches producing a substantially cylindrical work opening, connections between the members at one side of the opening, yielding means at the other side of the openin tending to press said members toward each other, and

an adjustable stop screw for limiting the degree to which said members may press toward each other.

10. A lap comprising a plurality of members whose contiguous faces are normally slightly separated and provided with complementary arches producing a round work opening, a spring tending to press said members toward each other, a screw for adjusting the tension of the spring, and adjustable means for positively limiting the action of the spring.

11. A lap comprising a plurality of members whose contiguous tacos are normally slightly separated and provided with complementary arches producing a round work opening, a spring tending to press said members toward each other and contract the size of said opening, means for adjusting the tension of said spring, and a screw threaded through one member and extends ing across said opening into contact with the other member, for the purpose set forth.

12. A lap comprisinga plurality of Infill" hers whose contiguous faces are normally slightly separated and provided with complementaryarches producing a round work opening, one member having a socket and the other a threaded opening opposite thereto, a screw whose head stands within said socket and whose shank extends across said opening 'between the members and engages the threaded opening in the other member, and

an expansive spring seated in said socket and plementary arches producing 'a round work opening, one member having a socket and the other a threaded opening opposite thereto, a screw whose head stands within said socket and whose shank extends across said opening between the members and engages the threaded opening in the other member, an expansive spring seated in said socket and coiledon the screw beneath its head, and a second screw threaded through one member and with its tip contacting with the other member, for the purpose set forth.

14. A lap comprising two members whose contiguous faces are normally spaced and are provided with complementary arches producing a substantially cylindrical work opening, one member having a hole through it leading into said opening, connections be tween the members at one side of the opening, a handle projecting from one member adjacent said connections, yielding means at the other side of the opening tending to press said members toward each other, and means for adjusting the tension of said yielding means.

15. A lap comprising two members whose contiguous faces are normally spaced and are provided with complementary arches producing a substantially, 'cylindrical work opening, one member having a hole through it leading into said opening, connections between the members. at one side of the opening, a handle projecting from one member adjacent said connectionsfy'ielding means at the other side of the opening tending to press said members toward each other, a screw for adjusting the tension Of-Sflld yielding means,

1 andan adjustable stop screw for limiting the degree to which said members may press toward each other.

16. An external lap comprising two members having their contiguous faces spaced and provided with complementary arches producing a round work-opening, a shank integrally connecting the members at one side. of said opening, a handle projecting from this end of theshank, one of the members at the other side of the opening having a socket and the other member. a threaded hole in line therewith, a screw whose head stands in the socket and whose shank engages the threads in said hole, and a coiled expansive spring seated in the socket and engaging the shank of the screw beneath its head.

17. In a lap, the combination with a body comprising a pair of arms integrally united at one end in a shank and having'parallel spaced jaws at their other end, the faces of the arms having complementary arches producing a round work opening, a slot extending thence toward the shank, and an enlargement within said shank, of a handle projecting from the shank end of the body, a spring tending to press said jaws toward each other, and means for adjusting the tension of the spring.

18. In a lap, the combinationwith a body comprising a pair of arms integrally united at one end in a shank and having parallel spaced jaws at their other end, the faces of the.arms having complementary arches producing a round work opening, a slot extending thence toward the shank, and an enlargement within said shank, of a screw adjustably seated in one'jaw, the other jaw having a socket loosely receiving the head of the screw, an expansive spring between the bottom of the socket and the head of said screw, and a second screw threaded through one jaw and having its tip bearing against the face of the other, all as and for the purpose set forth.

19. An external lap having an opening, lining members therein defining a work opening which is normally substantially cylindrical, and yielding means tending to reduce the size of said work opening below normal but permitting the increase of such size above normal.

20. An external lap comprising a plurality of jaws connected at one end and whose contiguous faces are normally separated and arched and the walls of the arches grooved on lines transverse to the plane of said jaws, and yielding means tending to press said members toward each other; combined with a lining made in members and each member provided with ribs removably engaging said grooves, said members defining an opening which is normally substantially cylindrical.

21. An external lap comprising a pair of jaws standing in one plane, connections between them at one end, and yielding means at the other end tending to press them toward each other, the contiguous faces of the jaws being normally out of contact and arched between their ends; combined with a lining made in two members internally shaped to define an opening which is normally substantially cylindrical, and means for detachably connecting each member with one jaw within its arch.

In testimony whereof we afiix our signatures.

LORENGE S. RASIWU SEN. HERMAN B. CARLSON. 

